hanoi.tiny

###############################################
#
# Towers of Hanoi
#
###############################################

numDisks = head(args) ?? 5

__global.MoveCount = 0;
fn dohanoi n, to, from, using ->
    if (n > 0) {
        n -= 1;
        dohanoi(n, using, from, to);
        println("move " + from + " ==> " + to);
        __global.MoveCount += 1
        dohanoi(n, to, using, from);
    }

println("Doing tower of hanoi with {0} disks:", numDisks); 
dohanoi(numdisks, 3, 1, 2);
println('Total moves: {0}', __global.MoveCount)
__global.Remove('MoveCount')

#
# Do it using a tower object
fn tower n -> {
    one:   n
    two:   0
    three: 0
    move:  {from to -> this.(from) -= 1; this.(two) += 1}
}

fn doHanoi tower, to, from, using ->
    if (tower.one > 0 || tower.two > 0) {
        tower.move("one", "three")
        tower.move("one", "two")
        tower.move("three", "two")
    }
}